1. Technical Field
Example embodiments of the present invention relate to methods of controlling interference between neighboring cells and apparatuses for managing interference.
2. Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) systems effectively manage neighboring cell's interference by defining inter-cell interference control information such as relative narrowband transmit power (RNTP), an RNTP threshold, an uplink (UL) high interference indication (HII), and a UL interference overload indication (IOI) and by causing the inter-cell interference control information to be exchanged between cells.
An RNTP value for a certain physical resource block (PRB) may be 0 or 1. Here, RNTP value 0 means that maximum transmit power of the PRB does not exceed a certain threshold, and RNTP value 1 means that the maximum transmit power is not limited. The RNTP threshold is a parameter which decides a threshold for the above-described maximum transmit power.
A UL HII value for the certain PRB may be 0 or 1. Here, UL HII value 0 indicates low interference sensitivity, and UL HII value 1 indicates high interference sensitivity.
A UL IOI value for the certain PRB may be one of values of high interference, medium interference, and low interference. The high interference means that neighboring cell's interference to the PRB is high, the low interference means that the neighboring cell's interference to the PRB is low, and the medium interference means that the neighboring cell's interference to the PRB is medium.
As defined above, RNTP, UL HII, and UL IOI can be differently set according to each PRB. Accordingly, an RNTP vector, a UL HII vector, a UL IOI vector, and the like can be defined. An jth element value of the RNTP vector is an RNTP value for an jth PRB. An jth element value of the UL HII vector is a UL HII value for the jth PRB. An jth element value of the UL IOI vector is a UL IOI value for the jth PRB.
In a scheme of a related art, the same RNTP vector, the same UL HII vector, the same UL IOI vector, and the same RNTP threshold are used throughout all subframes. That is, static interference management is performed in a time domain.
As a method of effectively handling neighboring cell's interference, there is a method of classifying radio resources into one or more radio resource groups, generating one or more radio resource attribute patterns from radio resource attributes, mapping radio resource attribute patterns to cell identities (IDs), and enabling each cell to use a radio resource according to a radio resource attribute pattern mapped to each cell's own cell ID.
The performance of the above-described method can be maximized when the following two items are optimally designed.                Radio resource attribute patterns to be used        Functions of defining mapping between radio resource attribute patterns and cell IDs        
However, the optimal radio resource attribute pattern and mapping are determined by various environmental factors, for example, a cell density, a frequency band used for radio resource, and the like.